The robotic garden tools, such as, but not limited to robotic lawnmowers are widely used for grass cutting applications in a lawn. As these robotic garden tools are autonomous, they have to navigate and keep a track of the areas they have performed operations upon. This is particularly important for the case in which the area to be mowed is very large. If the robotic garden tool does not keep the track of the locations it has performed operations upon and which are the remaining locations, then it may take long time to complete the operation in the whole area.
Normally wires are used to generate reference signals for the robotic garden tool to navigate the robotic garden tool in the lawn. But, the problem with such a system is that the signals generated may not provide any location based information as to where the robotic garden tool currently is. Also, these signals do not provide information as to whether a particular area is mowed and thus it might be possible that the robotic garden tool may mow a particular area multiple times, leading to inefficiency of the complete system.
The technique currently used to avoid the above mentioned problem is the use of navigation systems, such as, Global Positioning System (GPS). The GPS system may provide accurate data as to where the robotic garden tool is, the areas it has performed operations upon, areas remaining, etc. But the problem associated with such system is that it needs expensive GPS trans-receiver to be mounted on the robotic garden tool. Also, the interconnection between the GPS module and the other parts of the robotic garden tool adds to the complexity and the cost of the whole system. Further, if the contact to the GPS system is lost the robotic garden tool may not know its working area limits and might go off boundary.
In light of the foregoing, there is a need for an improved method for navigating the robotic garden tool in the lawn area, which will overcome the disadvantages of complex integration, increased cost, flexibility in cutting, along with optimally providing location based data.